It seems to be generally agreed that passive optical network(PON) is the best architecture for delivering broadband services. PONs being commercially available today are classified into two categories in terms of the multiple access technologies; one TDM-PON and the other WDM-PON. As good examples of TDM-PON, A/B-PON, E-PON, and G-PON are well known and already playing a key role in broadband access network services. However, it is quite likely that the TDM-PONs today can not support the bandwidth-exhausting multimedia services like IP-television, HD-quality VOD which are surely coming soon. Besides, TDM-PONs are never economical from the network investment point of view. In other words, TDM-PONs have not fully taken advantage of the optical fiber bandwidth, which is actually infinite. On the other hand, WDM-PON currently available offer enough bandwidth not only for present but also for future multimedia broadband services and fully utilize the optical fiber bandwidth.

The network architecture of WDM-PON is basically the same as that of TDM-PON. What is different is that WDM-PON assigns a wavelength to each subscriber while TDM-PON assigns a time-slot. Therefore, WDM-PON can be regarded as an aggregation of point-to-point connections between each subscriber and the central office. Fig. 1 illustrates the typical WDM-PON architecture.

For WDM-PON to be deployed in a large scale, it should offer at least the following features to service providers; 1) "Colorless OLT and ONU" : ONU or ONT should be able to operate in a colorless manner. That is, WDM-PON can be handled as simply and easily as TDM-PON like E-PON or G-PON. Otherwise, WDM-PON management would increase the operating as well as inventory costs.

2) "Working even in poor fiber plants" : Not like high quality fiber plant for core networks, the access network infrastructure is a little poor Usually the access network has problems caused by high optical loss and uncontrolled reflections, etc. Even in such environment, WDM-PON should work well!

3) "Cost-effective" : Cost-effectiveness is important, maybe the most important factor that service providers are considering. So, WDM-PON should be cost-competitive, being compared with its TDM-PON alternative like E-PON or G-PON.

Is there any WDM-PON to meet all these requirements?

BlueCross 1600 enables carriers to cost-effectively enhance their access network bandwidths. Some might still think WDM-PON is too expensive to actually deploy. But it is not the case for BlueCross 1600 at all. Since BlueCross 1600 consists of simpe, robust, and off-the-shelf optics, it could be deployed even at a lower cost than G-PON or E-PON.

The optical transceiver of BlueCross 1600 is tunable and emits one of 16 different wavelengths. So, it is virtually colorless, which means that we don't need to concern about wavelength-related things; wavelength assginment, matching, etc. BlueCross 1600 automatically sets and locks the transceiver's wavelength for each subscriber. This feature would save a great deal of CAPEX and OPEX!

Optical back reflection caused by poor fiber connections often leads to degradations in the traffic quality. In general, such degradations are quite unpredictable. But BlueCross 1600 is perfectly immune to the harmful reflections because it uses different wavelengths for up- and down- links, respectively, which enables to insert optical isolators in the optical path to prevent reflection. BleuPON 1600 is successfully working even under the reflection of 10dB!

BlueCross 1600 is capable of delivering the bidirectional 1Gbps speed per subscriber. Over the fiber length of 20km and under the worst reflection condition, no signal degradation has not been observed. As a next step, BlueCross 1600 is planned to provide the bidirectional 2.5Gbps speed per subscriber.

• Bidirectional optical link
• Downlink : Tunable 16 wavelengths in C-band
• Uplink : Tunable 16 wavelengths in C-band
• Rate per wavelength : 1.25Gbps (2.5Gbps optional)
• Output power: > +1dBm
• Receiver Sensitivity : -27dBm
• Span-length from OLT to ONU(T) : > 20km on conventional SMF
• Back reflection tolerence : > 10dB, error free

• WAN 8 ports
• LAN 24 ports
• VLAN (IEEE 802.1Q)
• QoS (IEEE 802.1p)
• DiffServ(DSCP)
• Bandwidth limiting
• Static routing
• IGMP snooping/PIM-SM
• DHCP server/relay
• Limiting the number of MACs
• GUI based Management

If you want more detailed technical information, the referece sites, or customization, feel free to contact us anytime. We would be very pleased to send you related documentation.